Calculating and Explaining Energy Change Flashcards
How can relative amounts of energy released be measured when substances burn?
Simple Calorimetry.
What can be calorimeter used for?
It can be used to compare the amount of energy released by fuels and foods.
What is energy measured in?
Joules (J).
How can the amount of energy released or absorbed by a chemical reaction be calculated?
It can be calculated from the measured temperature change of the solution when reagents are mixed in an insulated container. (This method can be used for reactions of solids with water or for neutralisation reactions).
What can be used to show the relative energies of reactants and products, the activation energy and the overall energy change of a reaction?
Simple energy level diagrams.
During a chemical reaction, what must be supplied to break bonds, and is released when bonds are formed?
Energy.
In exothermic reactions, which is greater the energy released when forming new bonds or the energy needed to break existing bonds?
The energy released when forming new bonds.
In endothermic reactions, which is greater the energy released when forming new bonds or the energy needed to break existing bonds?
The energy needed to break existing bonds.
What do catalysts provide?
A different pathway for a chemical reaction which has a low activation energy.
What fuel can be burned in combustion engines?
Hydrogen.
What fuel can be used in fuel cells that produce electricity to power vehicles?
Hydrogen.
